{"schema_version":"1.9.0","id":"GHSA-4vr5-p2gc-h23p","published":"2026-08-05T20:43:47Z","modified":"2026-09-10T03:50:53.313979835Z","aliases":["BIT-rclone-2026-59732","CVE-2026-59732","GO-2026-6185"],"summary":"rclone archive extract allows S3 destination prefix escape via crafted archive paths","details":"### Summary\n\n`rclone archive extract` can write extracted files outside the user-selected destination prefix when extracting a crafted archive. A malicious archive entry containing parent path components such as `../` can escape the requested extraction prefix and create or overwrite sibling objects in the same bucket/path scope.\n\n### Details\n\nThe affected code path is in `cmd/archive/extract/extract.go`.\n\nIn `ArchiveExtract()`, the archive entry path is taken from `f.NameInArchive`. The code strips only a leading `./` prefix and then joins the archive entry path with the destination directory:\n\n```go\nremote := f.NameInArchive\nremote = strings.TrimPrefix(remote, \"./\")\nif dstDir != \"\" {\n    remote = path.Join(dstDir, remote)\n}\n_, err = operations.Rcat(ctx, dst, remote, fin, f.ModTime(), nil)\n```\n\nParent path components such as `../` are not rejected before `path.Join()` is used.\n\nWhen the destination is an S3-style remote such as:\n\n```text\n:s3:bucket/safe/prefix\n```\n\nrclone creates the destination filesystem rooted at `bucket/safe` and treats `prefix` as the destination directory. If the archive contains an entry named:\n\n```text\n../escaped-from-prefix.txt\n```\n\nthen `path.Join(\"prefix\", \"../escaped-from-prefix.txt\")` resolves to:\n\n```text\nescaped-from-prefix.txt\n```\n\nAs a result, the S3 backend uploads the object to:\n\n```text\nbucket/safe/escaped-from-prefix.txt\n```\n\ninstead of the expected destination:\n\n```text\nbucket/safe/prefix/escaped-from-prefix.txt\n```\n\nThis allows an attacker-controlled archive to escape the selected extraction prefix on object-storage remotes.\n\n### PoC\n\nTest environment:\n\n- Windows 11\n- rclone v1.74.3 official Windows amd64 binary\n- Local fake S3 HTTP endpoint\n- Crafted ZIP archive containing `../escaped-from-prefix.txt`\n\nSteps to reproduce:https://drive.google.com/file/d/1P_cLKFgiWSVSATB8500yP28jdzwt9FAt/view?usp=sharing\n\n1. Extract the attached PoC ZIP.\n\n2. Run the PoC script:\n\n```powershell\npowershell -ExecutionPolicy Bypass -File .\\run-poc.ps1 -RcloneExe \"C:\\path\\to\\rclone.exe\"\n```\n\n3. The PoC creates a ZIP archive containing this entry:\n\n```text\n../escaped-from-prefix.txt\n```\n\n4. The PoC starts a local fake S3 endpoint and runs rclone with an S3-style destination prefix:\n\n```powershell\nrclone archive extract malicious.zip :s3:bucket/safe/prefix\n```\n\n5. Observe the fake S3 request log.\n\nExpected safe behavior:\n\n```text\nPUT /bucket/safe/prefix/escaped-from-prefix.txt\n```\n\nObserved behavior:\n\n```text\nPUT /bucket/safe/escaped-from-prefix.txt?x-id=PutObject\n```\n\nThis shows that the archive entry escaped the requested `safe/prefix` destination and was written under `safe/` instead.\n\nThe PoC package includes:\n\n- `run-poc.ps1`\n- `fake-s3-server.py`\n- `README.md`\n- `report-draft.md`\n- captured proof logs\n\n### Impact\n\nAn attacker who supplies an archive that a victim extracts with `rclone archive extract` can cause extracted files to be written outside the destination prefix selected by the victim when the destination is an S3-style object storage remote.\n\nDepending on the victim's configured remote credentials and bucket permissions, this may allow creation or overwrite of sibling objects outside the intended extraction directory/prefix.\n\nThis does not require compromising the S3 service itself. The attack relies on the victim extracting an attacker-controlled archive with rclone into an object-storage prefix.","affected":[{"package":{"name":"github.com/rclone/rclone","ecosystem":"Go","purl":"pkg:golang/github.com/rclone/rclone"},"ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.74.4"}]}],"database_specific":{"last_known_affected_version_range":"<= 1.74.3","source":"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/08/GHSA-4vr5-p2gc-h23p/GHSA-4vr5-p2gc-h23p.json"}}],"references":[{"type":"WEB","url":"https://github.com/rclone/rclone/security/advisories/GHSA-4vr5-p2gc-h23p"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59732"},{"type":"WEB","url":"https://github.com/rclone/rclone/commit/1a746732441e8158f32fab35924b23701e719a8c"},{"type":"WEB","url":"https://github.com/rclone/rclone/commit/d11efe0d58fe6a2d6d90675bb9d8ee5840c51e1d"},{"type":"PACKAGE","url":"https://github.com/rclone/rclone"},{"type":"WEB","url":"https://github.com/rclone/rclone/releases/tag/v1.74.4"}],"database_specific":{"cwe_ids":["CWE-22"],"github_reviewed":true,"github_reviewed_at":"2026-08-05T20:43:47Z","nvd_published_at":"2026-07-14T22:17:29Z","severity":"MODERATE"},"severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:L"}]}